Five network principles are elaborated from literature on Mexican immigrants and from research that I conducted on immigration from a rancho in Jalisco state to a variety of destinations within the United States. These principles are, first, that networks are multilocal, encompassing a number of geographical destinations. The importance of destinations, however, may change over time. Second, time ... [Show full abstract] anchoring points at any given geographical location are the work sites where immigrants find employment. Thus, labor market conditions structure where immigrants go and where they stay. Third, new geographical locations are often accessed through the 'strength of weak ties,' leading to geographic dispersion. Over time, some weak ties may be converted to strong ties though marriage or compadrazgo. Fourth, both dense networks and diffuse, weak-tie, or acquaintance networks constitute 'social capital' for their members. Fifth, given the geographical dispersion at the work site and/or work type clustering found among immigrants from any particular source community, the latter can best be explained by job recruitment primarily through dense network members, especially close relatives.